At present, existing portable fire extinguishing devices are generally divided into pressure-storage dry powder fire extinguishing devices and handheld aerosol fire extinguishing devices, wherein a pressure-storage dry powder fire extinguishing device mainly has the following disadvantages: firstly, the pressure-storage dry powder fire extinguishing device causes serious pollution to the environment and serious damage to materials; secondly, the pressure-storage dry powder fire extinguishing device, which needs to store high pressure gas, is large in volume and heavy in weight; thirdly, the pressure-storage dry powder fire extinguishing device, which is a high pressure container, has potential safety hazards and is more dangerous in a high temperature environment of a fire; fourthly, the pressure-storage dry powder fire extinguishing device, which needs to go through regular surveillance tests and inspections, is high in routine maintenance costs etc.
By contrast, a handheld aerosol fire extinguishing device has obvious advantages and overcomes the disadvantages existing in the pressure-storage dry powder fire extinguishing device. The handheld aerosol fire extinguishing device mainly comprises: a cartridge, a cartridge cover arranged on the cartridge, and a pyrotechnic composition, an ignition head, a coolant and a ceramic chip etc. arranged in the cartridge in turn and coated by a heat insulation material. Normally, after a pyrotechnic column is ignited by the ignition head, a great deal of aerosol smog will be generated by the cartridge through rapid stratified combustion, and after being cooled by a coolant layer, these high temperature aerosols will be ejected from the a spout of the cartridge cover of the cartridge to act on a fire source directly, thus extinguishing the fire.
However, the handheld aerosol fire extinguishing device also has some disadvantages. A coating defect, a pyrotechnic composition crack or a serious blockage of a gas channel may lead to a sudden rise of the pressure in the cartridge to deflagrate the pyrotechnic column. As a result, a high pressure gas will thrust the cartridge cover forwards and will be vented rapidly to cast the cartridge cover and other substances in the cartridge forwards at an extremely high speed, thus causing a very large recoil force. The powerful recoil force drives the cartridge to move backwards rapidly, which is easy to cause an injury to an operator. At the same time, after explosion venting, the cartridge cover of the fire extinguishing device etc. will also break away from the cartridge rapidly and fly outwards for a relatively long distance, which may also cause other accidents. In addition, the fire extinguishing device has a cylindrical casing, and a mould thereof is difficult to manufacture. Moreover, in order to enhance the structural strength of the casing, the wall thickness of the casing is not uniform at the top and the bottom, thus injection moulding processes are complicated. Further, when assembled, the cartridge needs to extend from one end of the cylindrical casing into the bottom of the casing and is fixed subsequently, which leads to complicated assembly processes on one hand, and the fixing effect of the cartridge is difficult to control on the other hand.